Self-Powered Wireless Sensor for Risk Assessment: Characterization and Implementation

This article introduces an electromagnetic vibration energy harvester and sensor assembly that is interfaced with a monitoring app for risk assessment of dynamic structures. The stand-alone energy harvester subassembly is used to power an amplitude modulated (AM) radio transmitter and microcontroller circuitry that can wirelessly transmit vibration sensor data using a sensor subassembly. The dual-mass moving magnets of the electromagnetic energy harvester and sensor assembly incorporate a directed magnet by a diaphragm-like moving FR4 spring. The transmitted sensor values are streamed into a PC where signal processing of the data takes place. The designed app can identify the vibration frequency of the sensor with high precision with an error as low as 0.1%. The total energy consumed to transmit a sensor value is approximately 0.9 μJ at an operating voltage of 3 V and minimum operable acceleration of 0.7g [m/s2].